Electronic pen and electronic pen main unit

ABSTRACT

In a case in which an electronic pen main unit made into a cartridge is held movably in a casing, electrical connections between the electronic pen main unit and electronic circuit components of the casing are reliably established. The electronic pen main unit is fitted to a fitting part disposed in a casing of an electronic pen in which the pen tip side is made to be an opening and is housed in a state of being movable in a hollow part of the casing by a movement mechanism that moves the fitting part in the axial center direction of the casing. The electronic pen main unit includes a pen tip part including an electrically-conductive core body allowed to protrude to the external through the opening by being moved by the movement mechanism, a main body tubular part to which the pen tip part is joined on the pen tip side in the axial center direction and that houses an electronic circuit including a signal generating circuit that generates a signal to be sent out to the external through the core body, and a rear-end-part connector that is disposed at a rear end part of the main body tubular part on the side opposite to the pen tip part in the axial center direction, includes a terminal connected to the electronic circuit, and is joined to a connector for joining disposed at the fitting part of the casing.

BACKGROUND Technical Field

This present disclosure relates to an electronic pen of a capacitivesystem that carries out transfer of signals with a position detectingsensor by electric field coupling and an electronic pen main unit.

Description of the Related Art

As an electronic pen of a capacitive system, an electronic pen of whatis called an active capacitive system that carries out transfer ofsignals (interaction) through electric field coupling with a positiondetecting sensor of a position detecting device to allow detection of aposition indicated by the electronic pen by the position detectingsensor has been favorably used.

In this kind of electronic pen of the active capacitive system, a powersupply circuit and a signal transmitting circuit using a primary cell orsecondary cell are incorporated. In addition, a core body is composed ofa conductor, and the electronic pen transmits a signal from the signaltransmitting circuit from the core body of the conductor to the positiondetecting sensor by capacitive coupling (for example, refer to PatentDocument 1 (Japanese Patent No. 5687398)).

PRIOR ART DOCUMENT Patent Document

Patent Document 1: Japanese Patent No. 5687398

BRIEF SUMMARY Technical Problems

Incidentally, due to preference for size reduction in recent years,requests for size reduction have become stronger also regarding portableelectronic equipment. Furthermore, the electronic pen has come to beused with a position detecting sensor mounted in this kind of small-sizeelectronic equipment, and ones with a thinner shape have been desirable.

Moreover, recently, the electronic pen has been regarded as an extensionof a writing material, and there has also been a demand for the internalconfiguration thereof to be modularized and be allowed to be treatedsimilarly to a replacement core (refill or cartridge) of a ballpointpen. Hereinafter, in this specification, what is configured to bereplaceable like a replacement core of a ballpoint pen throughmodularization and integration of internal constituent parts of anelectronic pen will be referred to as an electronic pen main unit.

In a case of attempting to configure the electronic pen of the activecapacitive system with such an electronic pen main unit housed in thecasing of the electronic pen, supply means of power to the signaltransmitting circuit housed in the electronic pen main unit becomes aproblem. That is, the electronic pen main unit in this case will have avery thin shape, and it is difficult to dispose a large-size primarycell in the electronic pen main unit. Even if it is possible to mount aprimary cell in the electronic pen main unit, its battery capacity issmall, requiring frequent replacement and causing unbearabletroublesomeness. Thus, a rechargeable small-size power storage elementor secondary cell should be disposed in the electronic pen main unit andbe charged externally. However, how to carry out the charging is aproblem.

Furthermore, in the electronic pen, there is also an electronic circuitcomponent that should be disposed on the casing of the electronic pen ina state of being operable by a user, such as a side switch, and how toimplement an electrical connection between the electronic circuitcomponent and an electronic circuit of the electronic pen main unit isalso a problem.

Moreover, in a case of configuring an electronic pen with use of such anelectronic pen main unit, it is also important to protrude the tip partof the electronic pen main unit from an opening of the casing of theelectronic pen to the external when the electronic pen is used similarlyto, for example, a knock-type ballpoint pen, in order to protect thethin tip part. However, in a case in which the electronic pen main unitmoves in the axial center direction in the casing of the electronic penin that way, how to make an electrical connection between the electronicpen main unit like the above-described one and the electronic circuitcomponent disposed on the casing of the electronic pen is a largeproblem.

This present disclosure provides an electronic pen and an electronic penmain unit that are enabled to solve the above problems.

Technical Solution

In order to solve the above-described problems, provided is anelectronic pen main unit that is fitted to a fitting part disposed in acasing of an electronic pen in which a pen tip side that is one end sidein an axial center direction is made to be an opening and is housed in astate of being movable in a hollow part of the casing by a movementmechanism that moves the fitting part in the axial center direction ofthe casing. The electronic pen main unit is characterized by including apen tip part including an electrically-conductive core body allowed toprotrude to external through the opening by being moved by the movementmechanism, a main body tubular part to which the pen tip part is joinedon the pen tip side in the axial center direction and that houses anelectronic circuit including a signal generating circuit that generatesa signal to be sent out to the external through the core body, and arear-end-part connector that is disposed at a rear end part of the mainbody tubular part on a side opposite to the pen tip part in the axialcenter direction, includes a terminal connected to the electroniccircuit, and is joined to a connector for joining disposed at thefitting part of the casing.

Furthermore, provided is an electronic pen that has a tubular casing inwhich an opening is made on one end side in the axial center directionthat is the pen tip side and in which at least one electronic pen mainunit is housed in the tubular casing. The electronic pen ischaracterized by including a fitting part to which a rear end part sideof the electronic pen main unit on the side opposite to the pen tip sideis fitted, and a movement mechanism that moves the fitting part in theaxial center direction of the casing, in which the fitting part includesa connector for joining including a terminal electrically connected toan electronic circuit component disposed on the casing, and theelectronic pen main unit includes a pen tip part including anelectrically-conductive core body allowed to protrude to the externalthrough the opening through movement of the fitting part by the movementmechanism, a main body tubular part to which the pen tip part is joinedon the pen tip side in the axial center direction and that houses anelectronic circuit including a signal generating circuit that generatesa signal to be sent out to the external through the core body, and arear-end-part connector that is disposed at a rear end part of the mainbody tubular part on the side opposite to the pen tip part in the axialcenter direction, includes a terminal connected to the electroniccircuit, and is joined to the connector for joining at the fitting partof the casing.

The electronic pen main unit with the above-described configuration isfitted to the fitting part that moves by the movement mechanism of theelectronic pen and moves in the axial center direction in the hollowpart of the casing of the electronic pen, and the pen tip part thereofis configured to be capable of protruding to the external from theopening of the casing.

Furthermore, the rear-end-part connector connected to the electroniccircuit disposed inside the electronic pen main unit is disposed at therear end part of the electronic pen main unit on the side opposite tothe pen tip side. Moreover, at the fitting part of the casing of theelectronic pen, the connector for joining to which electronic circuitcomponents such as an electrode for charging and a side switch disposedon the casing of the electronic pen are connected is disposed.

Therefore, the rear-end-part connector and the connector for joining arejoined when the rear end part of the electronic pen main unit is fittedto the fitting part of the casing of the electronic pen. Due to this,for example, a charging current supplied from the external to theelectrode for charging is supplied to a power storage element includedin the electronic circuit disposed inside the electronic pen main unitthrough the connector for joining and the rear-end-part connector, andthe power storage element is charged. Furthermore, for example, aterminal of the side switch is connected to the electronic circuitdisposed inside the electronic pen main unit through the connector forjoining and the rear-end-part connector. This allows the electroniccircuit to recognize a state of the side switch.

In the above-described configuration, the connector for joining isdisposed at the fitting part moved by the movement mechanism, and therear-end-part connector is disposed at the rear end part of theelectronic pen main unit fitted to this fitting part. Therefore, theelectronic pen main unit has a characteristic that the electricalconnection is always secured even when the electronic pen main unitmoves in the axial center direction in the casing of the electronic pen.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIGS. 1A and 1B depict diagrams for explaining a configuration exampleof a first embodiment of an electronic pen according to an embodimentdisclosed herein.

FIGS. 2A, 2B, and 2C depict diagrams for explaining a configurationexample of the first embodiment of an electronic pen main unit accordingto an embodiment disclosed herein.

FIGS. 3A and 3B depict diagrams for explaining a configuration exampleof the pen tip side of the first embodiment of the electronic pen mainunit according to an embodiment disclosed herein.

FIGS. 4A and 4B depict diagrams for explaining a configuration exampleof the first embodiment of the electronic pen main unit according to anembodiment disclosed herein.

FIG. 5 is a block diagram for explaining a configuration example of anelectronic circuit of the first embodiment of the electronic pen mainunit according to an embodiment disclosed herein.

FIG. 6 is a diagram for explaining a configuration example of a positiondetecting device of a capacitive system used with the first embodimentof the electronic pen according to an embodiment disclosed herein.

FIGS. 7A, 7B, 7C, 7D, 7E, and 7F depict diagrams used for explaining adetection method of a tilt angle of the electronic pen in the positiondetecting device of the example of FIG. 6 .

FIG. 8 is a diagram for explaining a configuration of a modificationexample of the first embodiment of the electronic pen main unitaccording to an embodiment disclosed herein.

FIG. 9 is a diagram for explaining a configuration example of anelectronic pen main unit used for a second embodiment of the electronicpen according to an embodiment disclosed herein.

FIGS. 10A, 10B, and 10C depict diagrams for explaining configurationexamples of other embodiments of the electronic pen main unit accordingto an embodiment disclosed herein.

FIGS. 11A, 11B, and 11C depict diagrams for explaining configurationexamples of other embodiments of the electronic pen according to anembodiment disclosed herein.

DETAILED DESCRIPTION

Embodiments of the electronic pen and the electronic pen main unitaccording to the present disclosure will be described below withreference to the drawings.

First Embodiment

An electronic pen of a first embodiment has a configuration in which anelectronic pen main unit made to have a configuration of a cartridgetype is housed in a tubular casing of the electronic pen attachably anddetachably.

Incidentally, in electronic pens of the active capacitive system ofrecent years, an electronic pen of a bidirectional communication typethat receives a signal from the side of a position detecting sensor thatdetects a position indicated by the electronic pen and transmits asignal of a format based on a request of the received signal has alsobeen developed.

In this kind of electronic pen of the bidirectional communication type,the position of a receiving part for receiving the signal from theposition detecting sensor is important. In a case of an electronic penof the capacitive system, the signal transmitted from the positiondetecting sensor is what is based on an electric field that can bereceived by capacitive coupling, and the reaching distance of the signalis very short. Thus, the receiving part of the electronic pen of thebidirectional communication type should be disposed at a position closeto the pen tip so that the signal from the position detecting sensor canbe received with high intensity.

Thus, in the electronic pen of this embodiment, the configuration of theelectronic pen main unit is considered to become the optimumconfiguration as one for the above-described electronic pen of thebidirectional communication type. Specifically, in the embodiment to bedescribed below, a receiving part of a signal from a position detectingsensor is disposed in the electronic pen main unit. This receiving partincludes a peripheral electrode composed of a tubular conductor disposedto surround a center electrode in such a manner as to cover the centerelectrode to the vicinity of the tip part of the center electrode whileelectrical insulation from the center electrode composed of anelectrically-conductive material is taken into consideration.

Furthermore, recently, a technique has been proposed in which the tiltangle with respect to the position detecting sensor surface regardingthe electronic pen (angle formed by the axial center direction of theelectronic pen and the position detecting sensor surface; hereinafterabbreviated as a tilt angle of the electronic pen) is detected by aposition detecting device and the detected tilt angle is reflected inthe thickness of an indication locus (writing trace) of the electronicpen, and so forth. In the electronic pen main unit of the electronic penof this embodiment, the above-described peripheral electrode isconfigured to be usable also for detection of a tilt angle of thiselectronic pen.

Furthermore, in this first embodiment, the peripheral electrode isconfigured to also play a role as a shield electrode for the centerelectrode that sends out a signal for position detection.

FIGS. 1A and 1B depict diagrams illustrating configuration examples ofthe first embodiment of the electronic pen according to an embodimentdisclosed herein. An electronic pen 1 of this first embodiment has aconfiguration of a knock system in which an electronic pen main unit 3is housed in a hollow part 2 a of a tubular casing 2 (hereinafter,referred to as a pen casing 2) and the pen tip side of the electronicpen main unit 3 is caused to protrude and retract from the side of anopening 2 b with a diameter R0 on one end side of the pen casing 2 inthe longitudinal direction by a knock cam mechanism unit 4 as an exampleof the movement mechanism.

FIG. 1A illustrates the state in which the whole of the electronic penmain unit 3 is housed in the hollow part 2 a of the pen casing 2, andFIG. 1B illustrates the state in which the pen tip side of theelectronic pen main unit 3 protrudes from the opening 2 b of the pencasing 2 due to the knock cam mechanism unit 4. In the example of FIGS.1A and 1B, the pen casing 2 of the electronic pen 1 is composed of atransparent synthetic resin and is illustrated to be in the state inwhich the inside thereof is visible in a see-through manner.

In this embodiment, the pen casing 2 and the knock cam mechanism unit 4disposed in the pen casing 2 are configured similarly to a knock-typeballpoint pen.

As illustrated in FIGS. 1A and 1B, the knock cam mechanism unit 4 has aconfiguration in which a cam main body 41, a knock bar 42, and a rotor43 are combined. The cam main body 41 is formed on the inner wallsurface of the tubular pen casing 2. In the knock bar 42, an end part 42a is allowed to protrude from an opening 2 c of the pen casing 2 on theside opposite to the pen tip side so that knock operation by the usercan be accepted. The rotor 43 has a fitting part 43 a to which the rearend part of the electronic pen main unit 3 on the side opposite to thepen tip side is fitted.

However, the fitting part 43 a is different from the fitting part of thecasing of the knock-type ballpoint pen of a normal writing material inthat a configuration of an electrical connection with the electronic penmain unit 3 is added to the fitting part 43 a. Specifically, asdescribed later, the electronic pen main unit 3 internally includes asignal transmitting circuit that generates a signal to be sent out tothe position detecting sensor through the center electrode or theperipheral electrode, and a supply voltage is provided to the signaltransmitting circuit.

In this embodiment, as described later, the signal transmitting circuitand a power storage element that supplies power to the signaltransmitting circuit are disposed inside the electronic pen main unit 3.Furthermore, the power storage element is charged from the external ofthe electronic pen main unit 3. Thus, a terminal conductor (electrode)connected to the power storage element is disposed at the end partfitted to the fitting part 43 a in the electronic pen main unit 3 ofthis embodiment, and a conductor connected to the terminal conductorconnected to the power storage element is formed at the fitting part 43a. The electrical configuration is added to the configuration of thejoined part to the electronic pen main unit 3, and the configuration ofthis joined part still remains a configuration to which a replacementcore of a ballpoint pen is joined and mounted. A configuration exampleof the end part fitted to the fitting part 43 a in the electronic penmain unit 3 will be described later together with a configurationexample of the fitting part 43 a.

Furthermore, at a part of the outer circumferential side surface on theside opposite to the pen tip side, in this example, in the pen casing 2,electrodes 2 d and 2 e for charging connected to a conductor disposed atthe fitting part 43 a are formed as illustrated in FIGS. 1A and 1B.

Moreover, a side switch 2S is disposed at a position on the outercircumferential side surface at which operation is allowed when the useruses the electronic pen 1 in the pen casing 2. The side switch 2S has aconfiguration of, for example, a push button switch or slide switch.

In the electronic pen 1 of this first embodiment, operation informationof the side switch 2S is transmitted to the electronic pen main unit 3through the fitting part 43 a. The electronic pen main unit 3 of thisfirst embodiment sends out this operation information of the side switch2S to the position detecting device in addition to the signal forposition detection and writing pressure information. Functionscorresponding to this operation information of the side switch 2S areset in the position detecting device, and the position detecting deviceexecutes processing according to the set functions in accordance withthe operation information of the side switch 2S received from theelectronic pen main unit 3.

Furthermore, in this embodiment, a conductor band 2 f is disposed at aposition on the outer circumferential side surface grasped by the userat the time of use in the pen casing 2. This conductor band 2 f is whatis formed of a tubular body composed of an electrically-conductivematerial such as electrically-conductive rubber, for example, and isdisposed to cover a partial outer circumference of the pen casing 2 inthe axial center direction. In this first embodiment, the conductor band2 f is configured to be connected to an earth electrode of theelectronic pen main unit 3 through the fitting part 43 a. The usergrasps the part of this conductor band 2 f at the time of use. Due tothis, the conductor band 2 f and the earth electrode of the electronicpen main unit 3 connected thereto (metal pipe part 31 a of a main bodytubular part 31 to be described later is also connected) are connectedto the ground (grounded) through the human body of the user.

In the electronic pen 1 with the above configuration, when the end part42 a of the knock bar 42 is pressed down in the state of FIG. 1A, theelectronic pen main unit 3 is locked to the state of FIG. 1B in the pencasing 2 by the knock cam mechanism unit 4, which makes the state inwhich the pen tip side of the electronic pen main unit 3 protrudes fromthe opening 2 b of the pen casing 2. Then, when the end part 42 a of theknock bar 42 is pressed down again from this state of FIG. 1B, thelocked state is released by the knock cam mechanism unit 4, and theposition of the electronic pen main unit 3 in the pen casing 2 returnsto the state of FIG. 1A by a spring 5 for return.

Embodiment of Electronic Pen Main Unit 3

FIG. 2A is a diagram illustrating an appearance configuration example ofthe electronic pen main unit 3 of this embodiment. Furthermore, FIG. 2Billustrates an electrical connection example at the joining part betweenthe electronic pen main unit 3 of this embodiment and the fitting part43 a of the casing 2 of the electronic pen 1. Furthermore, FIG. 2C is adiagram schematically illustrating the state in which the electroniccircuit inside the electronic pen main unit 3 and electronic circuitcomponents disposed on the pen casing 2 of the electronic pen 1 areelectrically connected when the electronic pen main unit 3 is fitted tothe fitting part 43 a.

The electronic pen main unit 3 of the electronic pen 1 of the firstembodiment is made to have a configuration that can establishcompatibility with a replacement core of a ballpoint pen except theconfiguration of the rear end side fitted to the fitting part 43 a ofthe pen casing 2. FIGS. 3A and 3B depicts diagrams illustrating aconfiguration example of the pen tip side of the electronic pen mainunit 3 of this embodiment, FIG. 3A is a diagram illustrating theappearance thereof, and FIG. 3B is a longitudinal sectional viewthereof. Furthermore, FIG. 4A depicts an exploded perspective view forexplaining a configuration example of the pen tip side of the electronicpen main unit 3 of this embodiment, illustrated in FIGS. 3A and 3B.

In the electronic pen main unit 3 of this embodiment, as illustrated inFIGS. 2A, 3A, and 3B, a peripheral electrode 33 composed of anelectrically-conductive component, for example, anelectrically-conductive metal, is joined to the pen tip side of the mainbody tubular part 31 with the interposition of a tubular joiningcomponent 32, so that a casing 30 (hereinafter, referred to as a mainunit casing 30) of the electronic pen main unit 3 is configured.

In this example, as illustrated in FIG. 2A, the main body tubular part31 is configured through joining of a resin pipe part 31 b to the rearend side of the metal pipe part 31 a on the side opposite to the pen tipside. Furthermore, in this example, for the main body tubular part 31,the peripheral electrode 33 is joined to the pen tip side of the metalpipe part 31 a with the interposition of the tubular joining component32. The tubular joining component 32 also plays a role in electricalinsulation between the metal pipe part 31 a and the peripheral electrode33. Moreover, at the rear end part of the resin pipe part 31 b, arear-end-part connector fitted to the fitting part 43 a disposed in thepen casing 2 of the electronic pen 1, a connector plug 50 in thisexample, is disposed. Meanwhile, at the fitting part 43 a of the pencasing 2, a joining connector joined to the rear-end-part connector ofthe electronic pen main unit 3, a connector jack 90 in this example, isdisposed.

In a hollow part 30 a of the main unit casing 30, as illustrated bydotted lines in FIG. 2A and FIG. 3A, a core body holding component 7, awriting pressure detecting unit 8, a printed board 9 on which the signaltransmitting circuit is mounted, and a rechargeable capacitor 10 as anexample of the power storage element for supply voltage provision aredisposed in such a manner as to be lined up in the axial centerdirection and be housed sequentially from the pen tip side.

This connector plug 50 includes multiple terminal parts, in thisexample, five terminal parts 51 a, 52 a, 53 a, 54 a, and 55 a, that areelectrically connected to the capacitor 10 housed in the electronic penmain unit 3 and the electronic circuit formed on the printed board 9,and are electrically insulated from each other.

In the electronic pen main unit 3 of this embodiment, the five terminalparts 51 a, 52 a, 53 a, 54 a, and 55 a of the connector plug 50 areconfigured as follows. Specifically, in this example, the terminal part51 a is composed of a conductor metal that configures a core bar at thecenter. Furthermore, in the example of FIG. 2A, the connector plug 50 isconfigured through combining of the terminal parts 52 a, 53 a, 54 a, and55 a that each have an inner wall surface on which an insulating layeris formed and have a cylindrical shape with the bar-shaped conductormetal of this terminal part 51 a in a concentric manner.

In this case, the terminal part 51 a of the conductor metal thatconfigures the core bar at the center is set as the tip part in theaxial center direction and its annular circumferential surface and tipare made to be exposed for a predetermined length in the axial centerdirection. In addition, in each of the cylindrical terminal parts 52 a,53 a, 54 a, and 55 a, its annular circumferential surface is made to beexposed for a predetermined length in the axial center direction. Thatis, the five terminal parts 51 a, 52 a, 53 a, 54 a, and 55 a of theconnector plug 50 are in the state in which circular annular conductorcontact parts are exposed at different positions in the axial centerdirection. The terminal part 51 a has a circular column shape and itsannular circumferential side surface and tip part configure theconductor contact part.

When this connector plug 50 is inserted into a fitting recess of theconnector jack 90 that configures the connector for joining formed atthe fitting part 43 a made on the rotor 43 disposed in the hollow partof the pen casing 2 of the electronic pen 1, as illustrated in FIG. 2B,the connector plug 50 enters the state of being elastically connected toeach of five contact terminals 91, 92, 93, 94, and 95 disposed in theconnector jack 90. Each of the five contact terminals 91, 92, 93, 94,and 95 is composed of an electrically-conductive elastic metal and iselectrically connected to a respective one of the electrodes 2 d and 2 efor charging, the side switch 2S, and the conductor band 2 f that aredisposed on the pen casing 2 (see FIG. 2C).

Therefore, through the insertion and joining of the connector plug 50into the connector jack 90, electronic circuit components inside theelectronic pen main unit 3 and electronic circuit components disposed onthe pen casing 2 of the electronic pen 1 are electrically connected.

As illustrated in FIG. 2C, in this embodiment, the terminal parts 51 a,52 a, 53 a, 54 a, and 55 a of the connector plug 50 are eachelectrically connected to a respective one of the electrodes 2 e and 2 dfor charging, both ends 2Sa and 2Sb of the side switch 2S, and theconductor band 2 f through the five contact terminals 91, 92, 93, 94,and 95 disposed in the connector jack 90 (diagrammatic representation ofthe contact terminals of the connector jack 90 is omitted in FIG. 2C).

At this time, the circular annular conductor contact parts of theterminal parts 51 a, 52 a, 53 a, 54 a, and 55 a of the connector plug 50are connected to the contact terminals 91, 92, 93, 94, and 95,respectively, of the connector jack 90. Therefore, even when theelectronic pen main unit 3 rotates around the center line in the axialcenter direction, the electrical connection is always kept, andelectrical non-contact can be avoided.

Due to the above configuration, when the electronic pen main unit 3 isfitted to the fitting part 43 a of the rotor 43 of the knock cammechanism unit 4 of the pen casing 2 of the electronic pen 1, both endsof the capacitor 10 housed in the electronic pen main unit 3 areconnected to the electrodes 2 d and 2 e for charging on the pen casing 2of the electronic pen 1. Due to this, when a supply voltage is notstored in the capacitor 10, the capacitor 10 is charged through theelectrodes 2 d and 2 e for charging, and a sufficient supply voltage isstored.

Furthermore, the electronic circuit of the electronic pen main unit 3becomes capable of detecting the state of the side switch 2S and cantransmit information regarding the detected state of the side switch 2Swith the information included in a signal sent out by a core body 35.Moreover, the earth electrode of the electronic pen main unit 3 and theconductor band 2 f of the pen casing 2 are electrically connected.Therefore, through grasping of the part of the conductor band 2 f by theuser, the earth electrode of the electronic pen main unit 3 can begrounded through the human body, and transmission and reception ofsignals from the electronic pen main unit 3 can be stably carried out.

Next, a configuration example of the pen tip side of the electronic penmain unit 3 of this embodiment will be further described with referenceto FIGS. 3A and 3B and FIGS. 4A and 4B.

In this example, as illustrated in FIGS. 2A, 2B, and 2C and FIGS. 3A and3B, the peripheral electrode 33 disposed on the pen tip side of the mainbody tubular part 31 is made into a shape having a cylindrical shapepart 33 a in which the outer diameter is constant and a tapered part 33b formed into a tapered shape in such a manner as to be graduallytapered toward the pen tip side. The metal pipe part 31 a of the mainbody tubular part 31 has a cylindrical shape with an outer diameterequal to an outer diameter R2 (>R1) of the cylindrical shape part 33 aof the peripheral electrode 33. For example, R2=2.2 millimeters is set.

The tubular joining component 32 is composed of an insulating material,resin in this example, and is a tubular body like one illustrated inFIG. 3B. At a middle position on its outer circumferential surface inthe axial center direction, a ring-shaped flange part 32F that protrudesfrom this outer circumferential side surface in the direction orthogonalto the axial center direction is formed. This ring-shaped flange part32F has a predetermined width W (see FIGS. 3A and 3B) in the axialcenter direction, and its end surface is flush with the main bodytubular part 31 and the peripheral electrode 33 without having any stepbeing generated and configures part of the main unit casing 30 asillustrated in FIGS. 3A and 3B. That is, the diameter of the outercircumferential part of the ring-shaped flange part 32F is selected tobe equal to the outer diameter of the peripheral electrode 33 and themetal pipe part 31 a of the main body tubular part 31.

Furthermore, the pen tip side, which is one side in the axial centerdirection, relative to the ring-shaped flange part 32F in this tubularjoining component 32 is made into a first fitting tubular part 32 afitted to the cylindrical shape part 33 a of the peripheral electrode33, and the configuration is made in such a manner that the cylindricalshape part 33 a of the peripheral electrode 33 is joined to the firstfitting tubular part 32 a through being press-fitted thereto untilreaching the place of the ring-shaped flange part 32F.

Moreover, the rear end side in the axial center direction relative tothe ring-shaped flange part 32F in the tubular joining component 32 ismade into a second fitting tubular part 32 b fitted to the metal pipepart 31 a of the main body tubular part 31, and the configuration ismade in such a manner that the metal pipe part 31 a of the main bodytubular part 31 is joined to the second fitting tubular part 32 bthrough being press-fitted thereto until reaching the place of thering-shaped flange part 32F.

In the state in which the metal pipe part 31 a of the main body tubularpart 31 and the peripheral electrode 33 are joined to the tubularjoining component 32, the main unit casing 30 of one tubular body isformed as illustrated in FIG. 2A and FIGS. 1A and 1B. Furthermore, themetal pipe part 31 a of the main body tubular part 31 composed of anelectrically-conductive material and the peripheral electrode 33 are notin contact and are in a state of being electrically isolated (insulated)from each other due to the existence of the ring-shaped flange part 32Fof the tubular joining component 32.

As illustrated in FIG. 3B, the hollow part 30 a exists inside the mainunit casing 30. Furthermore, a front cap 34 composed of an insulatingmaterial is mounted on the pen tip side of the peripheral electrode 33of the main unit casing 30 as illustrated in FIG. 2A and FIGS. 3A and3B. The front cap 34 has, on its tip side, an opening 34 a (see FIG. 3B)with a diameter larger than that of the center electrode 35 and theopening 34 a communicates with the hollow part 30 a of the main unitcasing 30.

The center electrode 35 is what configures a core body of the electronicpen main unit 3 of this embodiment and is composed of anelectrically-conductive component, in this example, anelectrically-conductive metal. Furthermore, as illustrated in FIG. 3B,this center electrode 35 is inserted into the main unit casing 30 fromthe opening 34 a of the front cap 34, and the end part on the sideopposite to the pen tip side is mounted to the core body holdingcomponent 7 attachably and detachably.

The core body 35 and the peripheral electrode 33 that are composed ofthe electrically-conductive material are electrically isolated(insulated) by the front cap 34 that is the insulating material asillustrated in FIG. 3B. In the electronic pen main unit 3 of thisembodiment, when the center electrode 35 is mounted, the peripheralelectrode 33 is disposed to surround the rear end side relative to a tippart 35 a that becomes the pen tip in the center electrode 35 asillustrated in FIG. 3B. In the following description, the centerelectrode 35 will be referred to as the core body 35.

The tapered part 33 b on the pen tip side in the peripheral electrode 33of the main unit casing 30 has a diameter that gradually becomes smalleras the position gets closer to the pen tip side. In this embodiment, asillustrated in FIG. 2A, the pen tip side relative to a middle positionin the axial center direction in the tapered part 33 b is configured tobe equal to or smaller than the diameter R0 of the opening 2 b on thepen tip side in the pen casing 2.

The electronic pen main unit 3 with the above configuration can behoused in the pen casing 2 by fitting its main body tubular part 31 tothe fitting part 43 a of the rotor 43 of the knock cam mechanism unit 4.Furthermore, in the electronic pen 1 of this embodiment, the userpresses down the end part 42 a of the knock bar 42 when using theelectronic pen 1 with a position detecting device. Thereupon, in theelectronic pen 1, the state is made in which, as illustrated in FIG. 1B,the tip part 35 a of the core body 35, the front cap 34, and a part ofthe pen tip side of the tapered part 33 b of the peripheral electrode 33protrude to the external from the opening 2 b of the pen casing 2.

After the use of the electronic pen 1 ends, by pressing down the endpart 42 a of the knock bar 42 again, the state can be made in which thewhole of the electronic pen main unit 3 is housed in the hollow part 2 aof the pen casing 2 as illustrated in FIG. 1A. At this time, the wholeof the electronic pen main unit 3 is housed in the hollow part 2 a ofthe pen casing 2, and the tip part 35 a of the core body 35 of theelectronic pen main unit 3 enters the state of being protected by thepen casing 2.

Moreover, in this embodiment, as illustrated in FIG. 3B, a board holder300 in which the printed board 9 is placed on a board placement pedestal301 is housed in the hollow part 30 a of the main unit casing 30.

The board holder 300 is composed of an insulating resin and has awriting pressure detecting unit holding part 302 for housing and holdingthe writing pressure detecting unit 8 on the side opposite to the sideof the board placement pedestal 301 in the longitudinal direction thatis the axial center direction of the electronic pen main unit 3. Asillustrated in FIG. 3B, the board holder 300 is made to have aconfiguration in which the writing pressure detecting unit holding part302 and the board placement pedestal 301 are continuous in thelongitudinal direction that is the axial center direction of theelectronic pen main unit 3 when the board holder 300 is housed in thehollow part of the main unit casing 30. The writing pressure detectingunit holding part 302 is made into a cylindrical shape having a hollowpart inside which multiple parts of the writing pressure detecting unit8 are housed. The board placement pedestal 301 is made into a shape thatis a boat shape on which the printed board 9 is placed to be held, andis like one obtained by cutting a tubular body by substantially halfalong the axial center direction.

The board holder 300 is housed in the main unit casing 30 in such amanner that the writing pressure detecting unit holding part 302 is seton the pen tip side. Furthermore, the configuration is made in such amanner that the core body holding component 7 that is fitted to the corebody 35 and holds the core body 35 is joined to the writing pressuredetecting unit 8 held by this writing pressure detecting unit holdingpart 302, and the pressure (writing pressure) applied to the core body35 is transmitted to the writing pressure detecting unit 8.

The board holder 300 is subjected to position restriction in such amanner as not to move in the axial center direction in the main unitcasing 30 through fitting and joining of the writing pressure detectingunit holding part 302 to the second fitting tubular part 32 b of thetubular joining component 32 in the axial center direction asillustrated in FIG. 3B.

Furthermore, although diagrammatic representation is omitted, both endsof the capacitor 10 disposed on the side opposite to the writingpressure detecting unit holding part 302 and copper foil patterns of apower supply line and an earth line of the printed board 9, on the boardplacement pedestal 301 of the board holder 300, are electricallyconnected. Due to this, the voltage of the capacitor 10 is supplied tothe circuit formed on the printed board 9 as a supply voltage.

In this embodiment, the metal pipe part 31 a of the main body tubularpart 31 composed of the electrically-conductive material is electricallyconnected to the copper foil pattern of the earth line of the printedboard 9.

In this embodiment, on the printed board 9, disposed is a circuit partthat is composed of the signal transmitting circuit that generatessignals to be sent out from the core body 35 and the peripheralelectrode 33, an IC (Integrated Circuit) 100 (see FIGS. 3A and 3B) thatconfigures a control circuit that controls transmission of the signalsfrom the signal transmitting circuit to the core body 35 and theperipheral electrode 33, and peripheral circuit part thereof. A chargingcircuit of the capacitor 10 is included in the peripheral circuit partalthough diagrammatic representation is omitted. The charging circuit ofthe capacitor 10 may be disposed outside the electronic pen 1.

As illustrated in FIG. 3B and an exploded perspective view of FIG. 4A,the core body holding component 7 that holds the core body 35 throughfitting is composed of an electrically-conductive elastic component 71,a core body holder 72, a coil spring 73, and a conductor terminalcomponent 74. The core body holding component 7 also plays a role as atransmitting component of the writing pressure applied to the core body35 for the writing pressure detecting unit 8.

In this embodiment, as illustrated in FIG. 3B and FIG. 4B, the core body35 is fitted into the core body holder 72 composed of anelectrically-conductive material through the electrically-conductiveelastic component 71 and is thereby joined to the core body holder 72 tobe held. The electrically-conductive elastic component 71 is composedof, for example, electrically-conductive rubber and is formed into acylindrical shape having a through-hole 71 a into which the end part ofthe core body 35 on the side opposite to the tip part 35 a is fitted.

The core body holder 72 is composed of an electrically-conductivematerial, for example, SUS (Steel Special Use Stainless), and is anobject in which a housing fitting part 721 having a recessed hole 721 ain which the electrically-conductive elastic component 71 is housed andfitted and a bar-shaped part 722 fitted into a holding component 83 tobe described later in the writing pressure detecting unit 8 aremonolithically formed.

Furthermore, the configuration is made in such a manner that thepressure (writing pressure) applied to the core body 35 is transmittedto the writing pressure detecting unit 8 through fitting of a tip part722 a of the bar-shaped part 722 of the core body holder 72 into theholding component 83 of the writing pressure detecting unit 8 held bythe writing pressure detecting unit holding part 302. In this case, theconfiguration is made in such a manner that the core body holder 72 isalways biased toward the side of the core body 35 against the boardholder 300 by the coil spring 73 as an example of an elastic componentcomposed of an electrically-conductive material such as anelectrically-conductive metal.

The coil spring 73 configures, with the conductor terminal component 74,a component for electrical connection for transmitting a signal from theIC 100 disposed on the printed board 9 to the core body 35. In theelectronic pen main unit 3 of this embodiment, a transmission signalgenerated by the signal transmitting circuit configured on the printedboard 9 is supplied to the core body 35 through the component forelectrical connection including this coil spring 73 and the conductorterminal component 74.

Specifically, in this embodiment, on the writing pressure detecting unitholding part 302 of the board holder 300, the conductor terminalcomponent 74 composed of a material having electrical conductivity, forexample, SUS, is mounted in such a manner as to cover the side of anopening 302 a into which the bar-shaped part 722 of the core body holder72 is inserted as illustrated in FIG. 4A.

As illustrated in FIGS. 4A and 4B, this conductor terminal component 74has an abutting plate part 741 that covers the side of the opening 302 aof the writing pressure detecting unit holding part 302 of the boardholder 300 and has a through-hole 741 a in which the bar-shaped part 722of the core body holder 72 is inserted.

Furthermore, an extending part 742 that extends to the part of the boardplacement pedestal 301 is disposed across the part of the writingpressure detecting unit holding part 302 of the board holder 300.Moreover, in the state in which the conductor terminal component 74 ismounted on the writing pressure detecting unit holding part 302 of theboard holder 300, as illustrated in FIG. 3B, a terminal part 742 a atthe tip of the extending part 742 that extends from the conductorterminal component 74 abuts against a conductor on the back surface sideof the printed board 9 placed on the board placement pedestal 301 of theboard holder 300 and is soldered thereto, for example. Due to this, theconductor terminal component 74 and the signal transmitting circuitdisposed on the printed board 9 are electrically connected.

The bar-shaped part 722 of the core body holder 72 into which theelectrically-conductive elastic component 71 is fitted is inserted intothe hollow part of the writing pressure detecting unit holding part 302of the board holder 300 through the through-hole 741 a of the abuttingplate part 741 of the conductor terminal component 74 and is fitted intothe writing pressure detecting unit holding part 302 in the state inwhich the coil spring 73 is interposed. The inner diameter of the coilspring 73 is set larger than the outer shape of the bar-shaped part 722of the core body holder 72.

The coil spring 73 elastically gets contact with the core body holder 72and abuts against and elastically gets contact with the abutting platepart 741 of the conductor terminal component 74. The coil spring 73 iscomposed of an electrically-conductive material, and theelectrically-conductive elastic component 71 and the core body holder 72have electrical conductivity. Thus, the signal transmitting circuitdisposed on the printed board 9 and the electrically-conductive elasticcomponent 71 fitted into the core body holder 72 are electricallyconnected through the conductor terminal component 74. Therefore,fitting of the core body 35 into the electrically-conductive elasticcomponent 71 makes the state in which a signal from the signaltransmitting circuit disposed on the printed board 9 is supplied to thecore body 35.

Next, description will be made about the configuration of the writingpressure detecting unit holding part 302 of the board holder 300 and thewriting pressure detecting unit 8 and fitting of the holding component83 of the writing pressure detecting unit 8 and the core body holder 72.

The writing pressure detecting unit 8 is housed in the writing pressuredetecting unit holding part 302, and the configuration is made asillustrated in FIG. 3B, thereby configuring a module for writingpressure detection. Furthermore, the core body 35 is joined to thismodule for writing pressure detection through the core body holder 72.Due to this, the writing pressure applied to the tip part 35 a of thecore body 35 is detected by the writing pressure detecting unit 8 of themodule for writing pressure detection. In this case, the module forwriting pressure detection detects the writing pressure through movementof a portion of the parts of the writing pressure detecting unit 8 thatconfigures the module in the axial center direction together with thecore body 35 and the core body holder 72 according to the writingpressure applied to the tip part 35 a of the core body 35.

The writing pressure detecting unit 8 of this example is a case in whicha capacitance-variable capacitor whose capacitance changes according tothe writing pressure applied to the core body 35 is used, and iscomposed of multiple parts, a dielectric 81, a terminal component 82,the holding component 83, an electrically-conductive component 84, andan elastic component 85, as illustrated in FIG. 3B.

In the state in which the core body holder 72 is fitted into the writingpressure detecting unit holding part 302 of the board holder 300 asabove, the core body 35 is press-fitted into the through-hole 71 a ofthe electrically-conductive elastic component 71 fitted into the corebody holder 72. Due to this, the core body 35 is firmly held withrespect to the core body holder 72 by the electrically-conductiveelastic component 71 as described above. The core body 35 can be pulledout in the direction toward the side of the tip part 35 a from the stateof being fitted into the core body holder 72 and being held and can bereplaced as described above.

In this electronic pen main unit 3, when a pressure is applied to thetip part 35 a of the core body 35, the core body 35 is displaced towardthe rear end side in the axial center direction according to thepressure. Due to this displacement, the holding component 83 in thewriting pressure detecting unit holding part 302 is displaced toward theside of the dielectric 81 against an elastic biasing force of theelastic component 85. As a result, the electrically-conductive component84 fitted into the holding component 83 is displaced toward the side ofthe dielectric 81, so that the distance between theelectrically-conductive component 84 and the dielectric 81 and thecontact area between the electrically-conductive component 84 and thedielectric 81 change according to the pressure applied to the core body35.

Due to this, the capacitance of a capacitance-variable capacitor formedbetween the terminal component 82 that configures a first electrode andthe electrically-conductive component 84 that configures a secondelectrode changes according to the pressure applied to the core body 35.This change in the capacitance of the capacitance-variable capacitor isdetected by the IC 100 disposed on the printed board 9, and the writingpressure is detected.

The writing pressure detecting unit 8 is not limited to one with theabove-described configuration. For example, one in which acapacitance-variable capacitor includes a semiconductor chip formed of aMEMS (Micro Electro Mechanical Systems) element (refer to patentdocument (Japanese Patent Laid-open No. 2013-161307), for example) maybe used.

Next, description will be made about the peripheral electrode 33 and anelectrical connection with the circuit part of the printed board 9. Inthe outer circumferential surface of the tubular joining component 32, arecessed groove (diagrammatic representation is omitted) is formed fromthe first fitting tubular part 32 a to the second fitting tubular part32 b by passing through the lower part of the ring-shaped flange part32F in the direction along the axial center direction of the tubularjoining component 32.

Furthermore, a recessed groove (diagrammatic representation is omitted)continuous with the recessed groove of the second fitting tubular part32 b is formed also in the circumferential side surface of the writingpressure detecting unit holding part 302 of the board holder 300. Inthis continuous recessed groove, as illustrated in FIG. 3B, a connectionterminal conductor 11 composed of an electrically-conductive material,in this example, an electrically-conductive metal, is disposed.Furthermore, as illustrated in FIG. 3B, an end part 11 a of theconnection terminal conductor 11 disposed in the recessed groove on theside of the first fitting tubular part 32 a of the tubular joiningcomponent 32 is disposed in such a manner that at least part of the endpart 11 a slightly bulges out relative to the outer circumferentialsurface of the first fitting tubular part 32 a. However, the depth ofthe recessed groove of the part of the end part 11 a is set to a depththat allows the end part 11 a to be elastically pressed downward whenthe end part 11 a is pressed down from above.

Due to this, the configuration is made in such a manner that the endpart 11 a of the connection terminal conductor 11 surely gets contactwith the inner wall of the peripheral electrode 33 and the state inwhich the peripheral electrode 33 and the connection terminal conductor11 are electrically connected is made when the peripheral electrode 33is fitted to the first fitting tubular part 32 a of the tubular joiningcomponent 32. Furthermore, an end part 11 b that extends to the side ofthe printed board 9 of the connection terminal conductor 11 iselectrically connected to the side of a back surface 9 b of the printedboard 9 as illustrated in FIG. 3B. Although diagrammatic representationis omitted, the end part 11 b of the connection terminal conductor 11 iselectrically connected to the circuit part on the front surface side ofthe printed board 9 via a through-hole.

The depth of the recessed groove in which the connection terminalconductor 11 is disposed is set to a depth with which the connectionterminal conductor 11 does not get contact with the metal pipe part 31 awhen the metal pipe part 31 a of the main body tubular part 31 is fittedto the second fitting tubular part 32 b. Alternatively, an insulator maybe interposed between the connection terminal conductor 11 and the metalpipe part 31 a.

Electronic Circuit Configuration Example of Electronic Pen Main Unit 3

Next, an electrical configuration example of the electronic pen mainunit 3 of this embodiment is illustrated in FIG. 5 . In this example, asillustrated in FIG. 5 , a control circuit 101 includes the IC 100disposed on the printed board 9. Furthermore, to this control circuit101, a signal transmitting circuit 102 and a signal receiving circuit103 are connected and a variable-capacitance capacitor 8C including thewriting pressure detecting unit 8 is connected. A resistor 8R isconnected in parallel to the variable-capacitance capacitor 8C.

Moreover, a signal output end of the signal transmitting circuit 102 isconnected to the core body 35 through a switch circuit 104. In thiscase, the interposition of the conductor terminal component 74, the corebody holder 72, and the electrically-conductive elastic component 71between the core body 35 and the switch circuit 104 is as describedabove.

Furthermore, in this example, the signal output end of the signaltransmitting circuit 102 is connected to a terminal S of a changeoverswitch circuit 105. A movable terminal M of this changeover switchcircuit 105 is connected to the peripheral electrode 33. In this case,the connection terminal conductor 11 is interposed between theperipheral electrode 33 and the changeover switch circuit 105.

A terminal R of the changeover switch circuit 105 is connected to aninput end of the signal receiving circuit 103. Furthermore, a terminal Gof the changeover switch circuit 105 is connected to an earth electrode(ground electrode).

Moreover, the control circuit 101 supplies the switch circuit 104 with acontrol signal SW1 that carries out on/off-control of the switch circuit104. Furthermore, the control circuit 101 supplies the changeover switchcircuit 105 with a changeover control signal SW2 to switch which of theterminal S, the terminal R, and the terminal G the movable terminal M isto be connected to.

Although diagrammatic representation is omitted, the voltage of thecapacitor 10 is supplied to each of the control circuit 101, the signaltransmitting circuit 102, the signal receiving circuit 103, the switchcircuit 104, and the changeover switch circuit 105 as a supply voltage.

The signal receiving circuit 103 receives a signal received by theperipheral electrode 33 through capacitive coupling (electric fieldcoupling) with a position detecting sensor of a position detectingdevice and executes processing of demodulation and so forth according tothe received signal to send a signal of the processing result to thecontrol circuit 101.

The control circuit 101 analyzes the signal from the signal receivingcircuit 103 and determines the specifications of the position detectingdevice of the counterpart. In addition, the control circuit 101 settlesthe timing at which interaction of a signal is carried out with theposition detecting sensor of the position detecting device of thecounterpart. Furthermore, the control circuit 101 controls the format ofa signal to be output from the signal transmitting circuit 102 in such amanner that the format becomes what matches the specifications of theposition detecting device of the counterpart and carries out interactionwith the position detecting sensor at the settled timing.

Basically, the signal transmitting circuit 102 outputs, under control ofthe control circuit 101, a signal including a signal for positiondetection (burst signal) with a predetermined frequency for positiondetection in the position detecting device and writing pressureinformation according to the writing pressure detected by the writingpressure detecting unit 8. Furthermore, the signal transmitting circuit102 outputs also a signal for detection of a tilt angle of theelectronic pen 1. That is, the signal transmitting circuit 102 sends outthe burst signal for position detection and the burst signal fordetection of the tilt angle of the electronic pen 1 under control by thecontrol circuit 101.

Moreover, in the period in which the burst signal for position detectionis being sent out from the signal transmitting circuit 102, the controlcircuit 101 carries out operation of detecting the writing pressure onthe basis of the capacitance of the variable-capacitance capacitor 8Cincluding the writing pressure detecting unit 8.

In this example, the control circuit 101 first charges thevariable-capacitance capacitor 8C to the fully-charged state andthereafter stops the charging to thereby set the variable-capacitancecapacitor 8C to the state of being discharged through the resistor 8R.Then, the control circuit 101 measures the time from the dischargingstart timing to the timing when the voltage across thevariable-capacitance capacitor 8C becomes a predetermined voltage set inadvance and detects the capacitance of the variable-capacitancecapacitor 8C at the time from the time. The capacitance of thevariable-capacitance capacitor 8C corresponds to the writing pressureapplied to the core body 35 at the time and detects the writing pressureon the basis of the detected capacitance.

The control circuit 101 converts the detected writing pressure to adigital signal of multiple bits in this example and controls the signaltransmitting circuit 102 to output writing pressure informationaccording to this digital signal from this signal transmitting circuit102.

Furthermore, a supply voltage Vcc stored in the capacitor 10 is suppliedto each of the control circuit 101, the signal transmitting circuit 102,the signal receiving circuit 103, the switch circuit 104, and thechangeover switch circuit 105. In this embodiment, a charging circuit106 of the capacitor 10 is disposed on the printed board 9 and isconnected to the terminals 52 a and 51 a of the connector plug 50 towhich the electrodes 2 d and 2 e for charging are connected. Therefore,although diagrammatic representation is omitted, when the electrodes 2 dand 2 e for charging are connected to an AC power supply through anadapter for charging, the capacitor 10 is charged by the chargingcircuit 106.

Moreover, the side switch 2S disposed on the pen casing 2 is connectedto the control circuit 101 through the terminals 53 a and 54 a of theconnector plug 50. The control circuit 101 determines the on- andoff-states of the side switch 2S and generates information regarding thedetermined state of the side switch 2S to transmit the generatedinformation regarding the state of the side switch 2S to the positiondetecting device through the signal transmitting circuit 102.

The earth electrode (ground conductor) of the electronic pen main unit 3is connected to the conductor band 2 f through the terminal 55 a of theconnector plug 50.

Circuit Configuration Example of Position Detecting Device

Next, a circuit configuration example of the position detecting deviceand the position detecting sensor will be described. FIG. 6 is a blockdiagram for explaining a configuration example of a reception processingcircuit of a signal from the electronic pen 1 in a position detectingdevice 200 of a capacitive system.

As illustrated in FIG. 6 , the position detecting device 200 of thisexample is composed of a position detecting sensor 210 and a pendetecting circuit 220 connected to this position detecting sensor 210.In this example, the position detecting sensor 210 is composed of afirst conductor group in which multiple first conductors 211Y₁, 211Y₂, .. . , 211Y_(m) (m is an integer equal to or larger than 1) that extendalong the horizontal direction (X-axis direction) are disposed in aY-axis direction in parallel separately from each other by apredetermined interval and a second conductor group in which multiplesecond conductors 212X₁, 212X₂, . . . , 212X_(n) (n is an integer equalto or larger than 1) that extend along the vertical direction (Y-axisdirection) are disposed in the X-axis direction in parallel separatelyfrom each other by a predetermined interval.

In the following description, when there is no need to distinguish themultiple first conductors of the first conductor group and the multiplesecond conductors of the second conductor group from one another, theconductors will be referred to as the first conductor 211Y and thesecond conductor 212X.

The pen detecting circuit 220 is composed of a selection circuit 221used as an input-output interface with the position detecting sensor210, an amplification circuit 222, a band-pass filter 223, a detectioncircuit 224, a sample-hold circuit 225, an AD (Analog to Digital)conversion circuit 226, and a control circuit 227.

The selection circuit 221 selects one conductor 211Y or 212X from thefirst conductor group and the second conductor group on the basis of acontrol signal from the control circuit 227. The conductor selected bythe selection circuit 221 is connected to the amplification circuit 222,and a signal from the electronic pen 1 (electronic pen main unit 3thereof) is detected by the selected conductor and is amplified by theamplification circuit 222. The output of this amplification circuit 222is supplied to the band-pass filter 223, and the component of thefrequency of the signal transmitted from the electronic pen 1 isextracted.

An output signal of the band-pass filter 223 is detected by thedetection circuit 224 and an output signal thereof is supplied to thesample-hold circuit 225 and is sampled and held by a sampling signalfrom the control circuit 227. Thereafter, the signal is converted to adigital value by the AD conversion circuit 226. Digital data from the ADconversion circuit 226 is read by the control circuit 227 and isprocessed.

The control circuit 227 sends out a control signal to each of thesample-hold circuit 225, the AD conversion circuit 226, and theselection circuit 221. In addition, the control circuit 227 calculatesposition coordinates on the position detecting sensor 210 indicated bythe electronic pen 1 from the digital data from the AD conversioncircuit 226 and detects writing pressure information.

Furthermore, the control circuit 227 detects a tilt angle of theelectronic pen 1 in a manner described below. A method of the detectionof the tilt angle of the electronic pen 1 in this position detectingdevice 200 will be described with reference to FIGS. 7A, 7B, 7C, 7D, 7E,and 7F.

When the core body 35 of the electronic pen main unit 3 of theelectronic pen 1 is in the perpendicular state with respect to the inputsurface of the position detecting sensor 210 as illustrated in aschematic diagram of FIG. 7A, in a position detection period Ta,capacitive coupling is made between the tip part 35 a of the core body35 and the position detecting sensor 210 and a region OBa in which thecapacitive coupling is made is a region of a true circle as illustratedin FIG. 7B. On the other hand, in a tilt detection period Tb, capacitivecoupling is made between the peripheral electrode 33 and the positiondetecting sensor 210 and a region OBa in which the capacitive couplingis made is a ring-shaped region as illustrated in FIG. 7C.

Furthermore, when the core body 35 of the electronic pen main unit 3 ofthe electronic pen 1 is in a tilt state with respect to the inputsurface of the position detecting sensor 210 as illustrated in aschematic diagram of FIG. 7D, the region OBa in which capacitivecoupling is made between the tip part 35 a of the core body 35 and theposition detecting sensor 210 in the position detection period Tasubstantially remains the region of the true circle as illustrated inFIG. 7E. On the other hand, the region OBb in which capacitive couplingis made between the peripheral electrode 33 and the position detectingsensor 210 in the tilt detection period Tb becomes a region of anelliptical shape that is according to the tilt angle and extends long inthe direction of the tilt as illustrated in FIG. 7F.

Therefore, in the control circuit 227 of the position detecting device200, the magnitude of the tilt angle of the electronic pen 1 can bedetected from the length in the major axis direction regarding theelliptical shape of the region OBb illustrated in FIG. 7F. Furthermore,the direction of the tilt of the electronic pen 1 can be detected bydetecting the major axis direction of the elliptical shape of the regionOBb with the indicated position of the electronic pen 1 illustrated inFIG. 7E being deemed as the point of origin.

In the above-described example, a signal with the same frequency as thesignal supplied to the core body 35 is used for the peripheral electrode33 used for detecting the tilt angle. However, the frequency of thesignal supplied to the core body 35 and the frequency of the signalsupplied to the peripheral electrode 33 may be made different. In thiscase, the signal from the core body 35 and the signal from theperipheral electrode 33 can be distinguished in the position detectingdevice 200. Thus, in the electronic pen main unit 3 of the electronicpen 1, the configuration may be made in such a manner that the signalfrom the core body 35 and the signal from the peripheral electrode 33are concurrently sent out to the position detecting sensor 210 insteadof carrying out the position detection period Ta and the tilt detectionperiod Tb in a time-sharing manner as described above.

Effects of First Embodiment

According to the electronic pen main unit 3 of the above-described firstembodiment, when the rear end part of the electronic pen main unit 3 isfitted to the fitting part 43 a of the pen casing 2, the connector plug50 of the electronic pen main unit 3 and the connector jack 90 of thefitting part 43 a are joined. Due to this, the electronic circuit insidethe electronic pen main unit 3 connected to the connector plug 50 of theelectronic pen main unit 3 and electronic circuit components such as theelectrodes 2 d and 2 e for charging, the side switch 2S, and theconductor band 2 f on the pen casing 2 connected to the connector jack90 of the pen casing 2 are electrically connected.

Furthermore, the connector jack 90 is disposed at the fitting part 43 amoved by the knock cam mechanism unit 4 as the movement mechanismdisposed in the pen casing 2, and the connector plug 50 is disposed atthe rear end part of the electronic pen main unit 3 fitted to thisfitting part. Therefore, the electrical connection is always securedeven when the electronic pen main unit 3 moves in the axial centerdirection in the pen casing 2.

Moreover, in the above-described embodiment, the circular annularconductor contact parts of the terminal parts 51 a, 52 a, 53 a, 54 a,and 55 a of the connector plug 50 are connected to the contact terminals91, 92, 93, 94, and 95, respectively, of the connector jack 90.Therefore, even when the electronic pen main unit 3 rotates around thecenter line in the axial center direction, the electrical connection isalways kept, and electrical non-contact can be avoided.

Furthermore, in the electronic pen 1 of this first embodiment, in use ofthe electronic pen 1 in which the pen tip side of the electronic penmain unit 3 protrudes to the external from the opening 2 b of the pencasing 2 of the electronic pen 1, not only the tip part 35 a of the corebody 35 but also part of the tapered part 33 b on the pen tip side inthe peripheral electrode 33 protrudes from the opening 2 b of the pencasing 2.

Therefore, according to the electronic pen 1 of this first embodiment,the distance between not only the tip part 35 a of the core body 35 andthe input surface of the position detecting sensor 210 but also thetapered part 33 b on the pen tip side in the peripheral electrode 33becomes short, and capacitive coupling (electric field coupling) betweenboth the two becomes strong. Moreover, in this embodiment, because thepen tip side of the peripheral electrode 33 is made into the taperedpart 33 b, the cross-sectional area of the tip part thereof on the pentip side is small, and the electric field coupling is made more stronglywith the position detecting sensor 210.

Therefore, the electronic pen 1 of this first embodiment can stronglymake electric field coupling with the position detecting sensor 210 evenwhen being made thinner. In the position detecting device 200, itbecomes possible to detect sensing of the position indicated by theelectronic pen 1 with high sensitivity. In addition, in the electronicpen main unit 3 of the electronic pen 1 of this first embodiment, asignal from the position detecting device 200 is received by theperipheral electrode 33, and the electronic pen main unit 3 startstransmission of a signal at a timing ordered by the received signal.This allows the position detecting device to wait for reception of thesignal from the electronic pen main unit 3 while predicting transmissionof the signal from the electronic pen main unit 3 of the electronic pen1, and favorable operation can be implemented even with the electricfield coupling with smaller coupling strength compared with theelectromagnetic induction system.

Another Example of Fitting Configuration Between Electronic Pen MainUnit and Fitting Part of Pen Casing

The connector plug 50 as an example of the rear-end-part connector ofthe electronic pen main unit 3 and the connector jack 90 as an exampleof the connector for joining at the fitting part 43 a of the pen casing2 are one example of the rear-end-part connector of the electronic penmain unit and the connector for joining at the fitting part of the pencasing, and the fitting configuration is not limited thereto.

FIG. 8 illustrates another example of the rear-end-part connector of theelectronic pen main unit and the connector for joining at the fittingpart of the pen casing. In an electronic pen main unit 3B of thisexample, the configuration of the rear-end-part connector is differentfrom the example of FIG. 2A, and the others are similar to theelectronic pen main unit 3 of the above-described first embodiment.Thus, in the following description, in the electronic pen main unit 3B,a constituent part similar to that of the electronic pen main unit 3 isgiven the same reference numeral, and detailed description thereof isomitted.

In the electronic pen main unit 3B of this example, a connector plug 50Bas an example of the rear-end-part connector is disposed at the rear endpart of the resin pipe part 31 b of the main body tubular part 31. Thisconnector plug 50B is what has a configuration similar to that of a pinplug for audio (for example, 5-pole pin plug with a noise cancellingfunction). In this example, five terminal parts 51 b, 52 b, 53 b, 54 b,and 55 b are in the state in which circular annular conductor contactparts with the same diameter are exposed at positions different in theaxial center direction.

Specifically, the terminal part 51 b at the tip of the five terminalparts 51 b, 52 b, 53 b, 54 b, and 55 b is made into a tip terminal. Themiddle three terminal parts 52 b, 53 b, and 54 b are each made into aring terminal insulated from other terminal parts by insulating rings 56a, 56 b, 56 c, and 56 d. The terminal part 55 b on the root side of theelectronic pen main unit 3B is made into a sleeve terminal.

A connector jack as an example of the connector for joining that isjoined to the connector plug 50B of the electronic pen main unit 3B ofthis example and is disposed at the fitting part 43 a of the pen casing2 includes five contact terminals that get contact with each of thecircular annular conductor contact parts of the five terminal parts 51b, 52 b, 53 b, 54 b, and 55 b and form an electrical connectionsimilarly to FIG. 2B although diagrammatic representation is omittedhere. Also in this example, the terminal parts 51 b, 52 b, 53 b, 54 b,and 55 b of the connector plug 50B are each electrically connected to arespective one of the electrodes 2 e and 2 d for charging, both ends 2Saand 2Sb of the side switch 2S, and the conductor band 2 f on the pencasing 2 through the five contact terminals disposed in the connectorjack.

Also in this example, the circular annular conductor contact parts ofthe terminal parts 51 b, 52 b, 53 b, 54 b, and 55 b of the connectorplug 50B are connected to a respective one of the five contact terminalsof the connector jack of the fitting part 43 a. Therefore, even when theelectronic pen main unit 3B rotates around the center line in the axialcenter direction, the electrical connection is always kept, andelectrical non-contact can be avoided.

In the above-described example, the rear-end-part connector of the rearend part on the side opposite to the pen tip side in the main bodytubular part 31 of the electronic pen main unit 3 or the electronic penmain unit 3B is made to have a configuration of a connector plug, andthe connector for joining at the fitting part 43 a of the pen casing 2is made to have a configuration of a connector jack. However,conversely, the rear-end-part connector of the electronic pen main unit3 or the electronic pen main unit 3B may be made to have a configurationof a connector jack, and the connector for joining at the fitting part43 a of the pen casing 2 may be made to have a configuration of aconnector plug.

Second Embodiment

An electronic pen of this second embodiment is a modification example ofthe first embodiment. In the above-described first embodiment, oneelectronic pen main unit 3 or electronic pen main unit 3B is housed inthe pen casing 2 of the electronic pen 1. In this second embodiment,multiple electronic pen main units are housed in a pen casing of anelectronic pen. Furthermore, by a knock mechanism as an example of themovement mechanism, one of the multiple electronic pen main units isselected, and the tip of the pen tip part of the selected electronic penmain unit is protruded from an opening of the casing on the pen tip sideand is used.

The electronic pen main unit 3 or the electronic pen main unit 3B of theelectronic pen 1 of the first embodiment is made to have a configurationthat can establish compatibility with a replacement core of a ballpointpen except the configuration of the rear end side fitted to the fittingpart 43 a of the pen casing 2. As a commercially-available ballpointpen, a multi-color ballpoint pen in which replacement cores different inthe ink color are mounted exists. This second embodiment provides anelectronic pen including housing the electronic pen main unit 3 in acasing with a configuration similar to that of the casing of thismulti-color ballpoint pen.

FIG. 9 is a configuration diagram illustrating the appearance of anelectronic pen 1M of this second embodiment. Also in this example ofFIG. 9 , a pen casing 2M of the electronic pen 1M is composed of atransparent synthetic resin and is illustrated to be in the state inwhich the inside thereof is visible in a see-through manner.

The pen casing 2M of the electronic pen 1M has almost the sameconfiguration as a casing and a knock mechanism of acommercially-available knock-type multi-color ballpoint pen. However,similarly to the pen casing 2 and the knock cam mechanism unit 4 of theelectronic pen 1 of the first embodiment, a configuration in whichelectrodes 2Md and 2Me for charging, a side switch 2MS, and a conductorband 2Mf are disposed on the pen casing 2M and a configuration of afitting part to which an electronic pen main unit 3AES is fitted in theknock mechanism are different from the casing and the knock mechanism ofthe commercially-available knock-type multi-color ballpoint pen.

In this example of FIG. 9 , in the pen casing 2M, one electronic penmain unit 3AES is housed and replacement cores of ballpoint pens of twocolors, for example, a replacement core 6R of a red ballpoint pen and areplacement core 6B of a black ballpoint pen, are housed. The electronicpen main unit 3AES is configured similarly to the electronic pen mainunit 3 or the electronic pen main unit 3B of the first embodiment exceptthat the electronic pen main unit 3AES is configured with the samedimensions as the replacement core of the multi-color ballpoint pen, andincludes a rear-end-part connector with a configuration similar to thatof the connector plug 50 or 50B, for example, on the rear end side ofthe main body tubular part 31.

Furthermore, the knock mechanism of the electronic pen 1M is equippedwith knock bars 42AES, 42R, and 42B to which the electronic pen mainunit 3AES and the replacement cores 6R and 6B of the red and blackballpoint pens, respectively, are fitted. A fitting part 43AES disposedon the knock bar 42AES is made to have a configuration including ajoining connector joined to the rear-end-part connector configured atthe rear end part of the electronic pen main unit 3AES similarly to thefitting part 43 a of the knock cam mechanism unit 4 in the firstembodiment. Therefore, the electrodes 2Md and 2Me for charging, the sideswitch 2MS, and the conductor band 2Mf are electrically connected tofive terminals of the connector for joining.

The fitting parts 43R and 43B of the knock bars 42R and 42B are madeinto fitting parts of a multi-color ballpoint pen.

Any of the knock bars 42AES, 42R, and 42B is moved by sliding toward thepen tip side, and thereby the pen tip side of the electronic pen mainunit 3AES or either the replacement core 6R or 6B of the red or blackballpoint pen protrudes from an opening 2Ma of the pen casing 2M.Furthermore, by the slide movement of the knock bar 42AES toward the pentip side, the tip part 35 a of the core body 35 and a part of theperipheral electrode 33 of the electronic pen main unit 3AES protrude tobe caused to make electric field coupling with a position detectingsensor of a position detecting device.

In a case of the electronic pen 1M of the second embodiment, theelectronic pen main unit 3AES and the replacement cores 6R and 6B ofballpoint pens are housed in the pen casing 2M, and therefore the axialcenter direction of the electronic pen main unit 3AES deviates from theopening 2Ma of the pen casing 2M. Thus, when the pen tip part of theelectronic pen main unit 3AES is let out and protruded from the opening2Ma of the pen casing 2M by using the knock mechanism, the electronicpen main unit 3AES pushed out slightly bends with respect to the fittingpart 43AES of the pen casing 2M.

However, the main body tubular part 31 of the electronic pen main unit3AES of this embodiment includes the resin pipe part 31 b. Therefore,due to the elasticity of this resin pipe part 31 b, it is possible todeal with the bending of the electronic pen main unit 3 at the time ofletting-out of the tip part of the electronic pen main unit 3. In a caseof dealing with a mechanism of the casing of a multi-color ballpoint penlike this second embodiment, it is preferable that the length of theresin pipe part 31 b in the axial center direction be adjusted to alength with which the bending at the time of letting-out of the tip partof the electronic pen main unit 3AES can be favorably absorbed by theresin pipe part 31 b.

In the above-described second embodiment, the fitting part 43AES of theknock bar 42AES in the three knock bars 42AES, 42R, and 42B is made tohave a configuration including a conductor to which the electronic penmain unit 3 or the electronic pen main unit 3B can be fitted. However,two or all of the fitting parts of the three knock bars 42AES, 42R, and42B may be made into ones for the electronic pen main unit 3 or theelectronic pen main unit 3B, and the fitting parts may be made into oneswith a configuration including a conductor. However, in the electronicpen main unit 3 or the electronic pen main unit 3B in this case, it ispreferable that an IC and a peripheral circuit thereof for implementinga function of transmitting its own identification information to aposition detecting device be disposed in the main unit casing 30 inwhich electronic circuit components are disposed.

In this case, the position detecting device used with the electronic penmain unit 3 or the electronic pen main unit 3B has a function ofreceiving and determining the identification information transmittedfrom each of the electronic pen main units 3 or the electronic pen mainunits 3B. Furthermore, the position detecting device determines thedifference among the electronic pen main units 3AES fitted to thefitting parts 43AES, 43R, and 43B and implements functions assigned tothe respective ones. For example, in a case in which all of the fittingparts of the three knock bars 42AES, 42R, and 42B are made into ones forthe electronic pen main unit 3 or the electronic pen main unit 3B, tothe electronic pen main unit fitted to the fitting part 43R, a functionof representing a writing locus (character or figure) displayedaccording to the indicated position thereof by red can be assigned.Furthermore, to the electronic pen main unit fitted to the fitting part43B, a function of representing a writing locus displayed according tothe indicated position thereof by black can be assigned. Moreover, tothe electronic pen main unit fitted to the fitting part 43AES, afunction of erasing a writing locus input through indication previouslyaccording to the indicated position thereof can be assigned.

The functions assigned to the electronic pen main units are not only thedisplay color of the locus according to the indicated position as inthis example and may be the kinds of displayed line, such as thethickness of a locus, a solid line, a dotted line, and a one-dot chainline.

When multiple electronic pen main units 3 or 3B are housed in the pencasing 2M, the electrodes 2Ed and 2Ee for charging and the conductorband 2Mf can be made common to these multiple electronic pen main units3 or 3B. Furthermore, the side switch 2MS may be made common to themultiple electronic pen main units 3 or 3B housed in the pen casing 2M,or multiple side switches may be disposed on the pen casing 2Mcorresponding to a respective one of the multiple electronic pen mainunits 3 or 3B housed in the pen casing 2M.

Furthermore, although the second embodiment is the example including thethree knock bars, the number of knock bars may be two or may be four ormore.

Other Embodiments of Electronic Pen Main Unit

In FIGS. 10A, 10B, and 10C, other embodiments of the electronic pen mainunit are illustrated. FIG. 10A illustrates a modification example ofanother example of the electronic pen main unit 3B illustrated in FIG. 8in the above-described first embodiment. This example is an exampleconfigured in consideration of common use with a replacement core of aballpoint pen similarly to the second embodiment. In description of anelectronic pen main unit 3C of this embodiment, a constituent partsimilar to that of the above-described electronic pen main unit 3B isgiven the same reference numeral, and detailed description thereof isomitted.

In the electronic pen main unit 3C of this embodiment, a peripheralelectrode 33C with a different shape from the peripheral electrode 33 ofthe electronic pen main unit 3B of the first embodiment is used.Specifically, as illustrated in FIG. 10A, the peripheral electrode 33Cof the electronic pen main unit 3C of this embodiment is made into atubular shape whose outer diameter is constant in the axial centerdirection, and the outer diameter is set to a diameter R1 smaller thanthe diameter of the opening 2 b (see FIGS. 1A and 1B) of the pen casing2 of the electronic pen.

Thus, in the electronic pen main unit 3C of this embodiment, because theconfiguration of the peripheral electrode 33C is different from that ofthe electronic pen main unit 3 in the first embodiment, a tubularjoining component 32C that joins the peripheral electrode 33C to themain body tubular part 31 is configured in conformity to theconfiguration of the peripheral electrode 33C in such a manner that theperipheral electrode 33C can be joined to the main body tubular part 31with the interposition of a ring-shaped flange part 32CF. Furthermore, afront cap 34C is also configured with change in conformity to theconfiguration of the peripheral electrode 33C. The others are made tohave a configuration similar to that of the electronic pen main unit 3of the first embodiment.

On the rear end side of the electronic pen main unit 3C in this exampleof FIG. 10A, the connector plug 50B as an example of the rear-end-partconnector is disposed in this example similarly to the electronic penmain unit 3B. Furthermore, the electronic pen main unit 3C is fitted tothe fitting part 43 a of the pen casing 2 of the electronic pen 1 andthe connector plug 50B as an example of the rear-end-part connector iselectrically connected to a connector jack as an example of theconnector for joining at the fitting part 43 a.

Therefore, also in the electronic pen using the electronic pen main unit3C of this example of FIG. 10A, the same operation and effects as theelectronic pen 1 of the first embodiment can be obtained. At the time ofuse, the core body 35, the front cap 34C, and a part of the peripheralelectrode 33C on the pen tip side protrude to the external from anopening of a casing 2C of the electronic pen illustrated by dotted linesin FIG. 10A. In this case, the cylindrical part with the constant outerdiameter in the peripheral electrode 33C is located at the part ofopening of the casing 2C. Therefore, by adjusting the outer diameter ofthe cylindrical part of this peripheral electrode 33C, the pen tip sideof the electronic pen main unit 3C can be easily kept from involving abacklash in the opening of the casing 2C.

Next, an example of FIG. 10B also illustrates a modification example ofanother example of the electronic pen main unit 3B illustrated in FIG. 8in the above-described first embodiment. Parts of a main body tubularpart 31D and a tubular joining component 32D of an electronic pen mainunit 3D of this embodiment are different from the above-describedelectronic pen main unit 3B, and the other part is made into a similarconfiguration. Thus, also in the electronic pen main unit 3D of thisembodiment, a constituent part similar to that of the electronic penmain unit 3B is given the same reference numeral and detaileddescription thereof is omitted.

The main body tubular part 31D of the electronic pen main unit 3D ofthis embodiment has an outer diameter R3 larger than the outer diameterR2 of the main body tubular part 31 of the above-described electronicpen main unit 3B. Furthermore, the inner diameter of the main bodytubular part 31D of the electronic pen main unit 3D of this embodimentis set to a diameter larger than the inner diameter of the main bodytubular part 31 of the electronic pen main unit 3 of the firstembodiment.

Thus, in the electronic pen main unit 3D of this embodiment, because theconfiguration of the main body tubular part 31D is different from thatof the electronic pen main unit 3B, the tubular joining component 32Dthat joins the peripheral electrode 33 to the main body tubular part 31Dis configured in conformity to the configuration of the main bodytubular part 31D in such a manner that the peripheral electrode 33 canbe joined to the main body tubular part 31D with the interposition of aring-shaped flange part 32DF.

The main body tubular part 31D of the electronic pen main unit 3D ofthis embodiment includes a hollow part with a large space. Furthermore,in the electronic pen main unit 3D of this embodiment, by use of thespace of the large hollow part of this main body tubular part 31D, theconfiguration is made in such a manner that a primary cell (battery)10BT is housed in the hollow part as illustrated in FIG. 10B instead ofthe capacitor 10 as the power storage element used in theabove-described electronic pen main unit 3B. The other electroniccircuit components in the main body tubular part 31D are housed in themain body tubular part 31D similarly to the first embodiment, and thesupply voltage to the respective parts is supplied from the primary cell10BT incorporated in the main body tubular part 31D. Therefore, theelectrodes 2 d and 2 e for charging do not need to be disposed on thepen casing 2D of the electronic pen 1 using the electronic pen main unit3D of this embodiment.

In this example, the main body tubular part 31D of the electronic penmain unit 3D of this embodiment is formed of a metal pipe. In addition,on the rear end part thereof on the side opposite to the pen tip side, acomponent 31DE in which a connector plug 50B′ as an example of therear-end-part connector is formed on a resin base 31Da is mountedattachably and detachably. In the electronic pen main unit 3D of thisembodiment, the configuration is made in such a manner that the primarycell 10BT housed in the main body tubular part 31D can be replacedthrough removal of the component 31DE.

The casing of the electronic pen that houses the electronic pen mainunit 3D of this embodiment is set to a diameter larger than that of thecasing 2 of the electronic pen of the above-described first embodiment.The other configuration of the casing of the electronic pen is madesimilar to the above-described embodiment and includes a movementmechanism such as a knock cam mechanism or knock mechanism. At a fittingpart moved by the movement mechanism, a connector jack to which theconnector plug 50B′ of the rear end part of the electronic pen main unit3D is joined and that is electrically connected to a side switch and theconductor band 2 f is disposed.

Also in a case in which the main body tubular part 31D is configuredinto a thick shape as in the electronic pen main unit 3D of thisembodiment, a secondary cell or a power storage element such as acapacitor may be disposed instead of disposing the primary cell 10BT inthe hollow part of the main body tubular part 31D. In this case, theconfiguration of the rear-end-part connector of the main body tubularpart 31D of the electronic pen main unit 3D is configured similarly tothe electronic pen main unit or the electronic pen main unit 3B of thefirst embodiment, and the electrodes 2 d and 2 e for charging aredisposed on the casing 2 of the electronic pen.

Also in the electronic pen using the electronic pen main unit 3D of thisexample of FIG. 10B, the operation and effects similar to the electronicpen 1 of the first embodiment can be obtained. At the time of use, thecore body 35, the front cap 34, and a part of the tapered part of theperipheral electrode 33 on the pen tip side protrude to the externalfrom an opening of a casing 2D of the electronic pen illustrated bydotted lines in FIG. 10B.

FIG. 10C is a modification example of the electronic pen main unit 3C ofFIG. 10A. A peripheral electrode 33C′ of an electronic pen main unit 3C′of this example of FIG. 10C is different from the peripheral electrode33C of the electronic pen main unit 3 of the example of FIG. 10A in thatthe pen tip side is made into a tapered part 33C′b. Specifically, theperipheral electrode 33C′ of the electronic pen main unit 3C′ of thisexample is made into a shape in which the tapered part 33C′b is formedon the pen tip side of a cylindrical shape part 33C′ a whose outerdiameter is set to the diameter R1 smaller than the diameter R0 of theopening 2 b (see FIGS. 1A and 1B) of the pen casing 2 of the electronicpen. In this example, a front cap 34C′ is disposed on the tip part ofthe tapered part 33C′b of the peripheral electrode 33C′. The others areconfigured similarly to the electronic pen main unit 3C of the exampleof FIG. 10A.

Also in a case of the electronic pen main unit 3C′ of this example ofFIG. 10C, at the time of use, the core body 35, the front cap 34C′, anda part of the peripheral electrode 33C′ on the pen tip side protrude tothe external from the opening of the casing 2C of the electronic pen. Inthis case, the part of the peripheral electrode 33C′ that protrudes tothe external includes not only the tapered part 33C′b but also a part ofthe cylindrical shape part 33C′ a, and the part located at the openingof the casing 2C is the cylindrical shape part 33C′ a. Therefore, theoperation and effects similar to the example of FIG. 10A are provided.

Other Embodiments of Electronic Pen

Several of other configuration examples of the electronic pen includingfitting the rear-end-part connector included in the electronic pen mainunit to the fitting part that is movable in the casing by the movementmechanism and includes the connector for joining as described above willbe described with reference to schematic configuration examplesillustrated in FIGS. 11A, 11B, and 11C.

An electronic pen main unit 3E housed in an electronic pen 1Eillustrated in FIG. 11A is different from the electronic pen main unitsof the above-described embodiments in that a supply voltage is obtainedfrom a secondary cell (rechargeable battery) 12BT disposed in a casing2E, and the others are made into a similar configuration.

In the electronic pen casing 2E of this example, a connector 90E forjoining is disposed at a fitting part 43E moved by a knock bar 42E. Inthis connector 90E for joining, a terminal for supplying the supplyvoltage from the secondary cell 12BT to an electronic circuit inside theelectronic pen main unit 3E and, in this example, a terminal to which aside switch 2ES is connected, are disposed. The conductor band 2 f maybe disposed on the pen casing 2E, and a terminal for connecting theconductor band 2 f and an earth electrode of the electronic pen mainunit 3E may be disposed.

When a rear-end-part connector 50E of the electronic pen main unit 3E isfitted to the fitting part 43E as illustrated in FIG. 11A, therear-end-part connector 50E is joined to the connector 90E for joiningdisposed at the fitting part 43E, and the supply voltage from thesecondary cell 12BT is supplied to the electronic circuit of theelectronic pen main unit 3E. In addition, the side switch 2ES isconnected to the electronic circuit, and the state thereof is allowed tobe detected.

In this example, the secondary cell 12BT is configured to be chargedfrom the external through electrodes 2Ed and 2Ee for charging.

According to this example, a power supply does not need to be disposedin the main body tubular part of the electronic pen main unit 3E, andtherefore the configuration of the electronic pen main unit 3E can besimplified.

Because the secondary cell 12BT is used in the example of FIG. 11A, theelectrodes 2Ed and 2Ee for charging are disposed on the pen casing 2E.However, a primary cell may be used instead of the secondary cell 12BT.In this case, the electrodes 2Ed and 2Ee for charging becomeunnecessary.

Next, FIG. 11B is a modification example of the electronic pen 1E of theexample of FIG. 11A. In an electronic pen 1F of this example of FIG.11B, the charging method of the secondary cell 12BT disposed in a pencasing 2F is different from the electronic pen 1E, and the otherconfiguration is similar to the electronic pen 1E.

In the electronic pen 1F of this example, as illustrated in FIG. 11B, acore 13 is fitted and attached to the outer circumferential side surfaceof the pen casing 2F, and a coil 14 for charging is wound and disposedaround this core 13. Furthermore, in the electronic pen 1F of thisexample, a configuration in which electromagnetic energy supplied fromthe external is received by the coil 14 for charging and the secondarycell 12BT is charged is made.

In the electronic pen 1F of this example, a movement mechanism has aconfiguration using a knock bar 42F of a slide system. A connector 90Ffor joining is formed at a fitting part 43F moved in response to slidemovement of this knock bar 42F and is configured to be joined to arear-end-part connector 50F of an electronic pen main unit 3F. Also inthe electronic pen 1F of this example, a movement mechanism based on aknock bar pushed from the rear end side of the pen casing 2F like thatillustrated in FIG. 11A may be used. Furthermore, also in the electronicpen 1E of the example of FIG. 11A, it is also possible to make theconfiguration in such a manner that a movement mechanism using a knockbar of a slide system like that in FIG. 11B is used. In addition, in theexample of FIG. 11B, the secondary cell 12BT is disposed in the casing2F of the electronic pen 1F. However, the configuration may be made insuch a manner that a secondary cell is disposed in the electronic penmain unit 3F and is charged by a charging current from the charging coil14.

Moreover, an electronic pen 1G of an example of FIG. 11C is differentfrom the electronic pen 1F of the example of FIG. 11B in that anelectronic circuit 15 is disposed in a pen casing 2G and the side switch2S is connected to the electronic circuit 15 through not a connector forjoining but, for example, a flexible cable, and the others are made intoa similar configuration. Furthermore, in the electronic pen 1G of thisexample, a connector 90G for joining and a rear-end-part connector 50Gof an electronic pen main unit 3G are joined, and the electronic penmain unit 3G and electronic circuit components disposed on the pencasing 2G are electrically connected through a flexible cable or thelike.

In the electronic pen 1G of this example, a voltage from the secondarycell 12BT disposed in the pen casing 2G is supplied to an electroniccircuit of the electronic pen main unit 3G as a supply voltage similarlyto the electronic pens 1E and 1F of the above-described examples. Inaddition, in the electronic pen 1G of this example, the voltage from thesecondary cell 12BT is supplied to the electronic circuit 15 as a supplyvoltage.

In this electronic circuit 15, a control part formed of an IC isdisposed and a wireless communication part that carries out wirelesscommunication of, for example, the Bluetooth (registered trademark)standard is disposed to be connected to the control part. This wirelesscommunication part is what is for carrying out wireless communicationbetween the electronic pen 1G and a position detecting device of acapacitive coupling system similarly to the above-described embodiments.Furthermore, the control part of the electronic circuit 15 is connectedto a terminal part including a circular annular conductor contact partof the connector 90G for joining.

In addition, in the electronic pen 1G of this example, the side switch2S is connected to the control part, and the configuration is made insuch a manner that operation information of this side switch 2S iswirelessly transmitted to the position detecting device of thecapacitive coupling system.

Moreover, in the electronic pen 1G of the example of FIG. 11C, theelectronic circuit 15 disposed in the pen casing 2G is configured toacquire writing pressure information detected by the electronic circuitof the electronic pen main unit 3G through the rear-end-part connector50G and the connector 90G for joining and wirelessly transmit thewriting pressure information to the position detecting device of thecapacitive coupling system. Therefore, the writing pressure informationdoes not need to be included in a signal for position detection sent outfrom the core body 35 of the electronic pen main unit 3G of thisexample. Also in the electronic pen 1G of this example, the writingpressure information may be included in the signal for positiondetection sent out from the core body 35 of the electronic pen main unit3G and be sent out.

Also in the electronic pen 1G of this example, a movement mechanismbased on a knock bar pushed from the rear end side of the pen casing 2Flike that illustrated in FIG. 11A may be used.

Furthermore, in the configuration of the electronic pen 1G of thisexample of FIG. 11C, it is also possible to make the configuration asfollows by using the electronic circuit 15.

Specifically, a memory that stores identification information (pen ID)of the electronic pen 1G may be disposed to be connected to the controlpart of the electronic circuit 15, and a position detecting device maybe notified of the pen ID through the wireless communication part.

Furthermore, a memory that stores identification information (pen mainunit ID) of the electronic pen main unit 3G is disposed in theelectronic circuit of the electronic pen main unit 3G, and the pen mainunit ID in this memory is supplied to the electronic circuit 15 disposedin the pen casing 2G through the rear-end-part connector 50G and theconnector 90G for joining. Then, this electronic circuit 15 may notifythe pen main unit ID to the position detecting device through thewireless communication part.

Moreover, in the electronic circuit of the electronic pen main unit 3G,a signal sent out from a position detecting sensor of the positiondetecting device is received by the peripheral electrode 33, and thesignal level of the signal received by a receiving part thereof isdetected. Then, it is detected whether the electronic pen 1G is in anin-range state in which the electronic pen 1G makes capacitive couplingwith the position detecting sensor or an out-range state in which theelectronic pen 1G is not coupled with the position detecting sensor, anda detection signal thereof is supplied to the electronic circuit 15disposed in the pen casing 2G through the rear-end-part connector 50Gand the connector 90G for joining. Then, this electronic circuit 15 maynotify whether the electronic pen 1G is in the in-range state or theout-range state to the position detecting device through the wirelesscommunication part.

OTHER EMBODIMENTS OR MODIFICATION EXAMPLES

In the above-described embodiments, the peripheral electrode is composedof a tubular conductor. However, the peripheral electrode may be what isconfigured into a tubular shape by a conductor divided into multiplepieces in the circumferential direction.

Furthermore, the core body 35 is composed of an electrically-conductivemetal. However, it is sufficient for the core body 35 to be what haselectrical conductivity. Therefore, the core body 35 may include a hardresin into which conductor powders are mixed, for example.

The main body tubular part of the electronic pen main unit may include asingle body of a resin pipe instead of the configuration in which themetal pipe part and the resin pipe part are joined. Moreover, the rearend side of the main body tubular part does not need to have the pipeshape, and it is sufficient that the rear end side can be made into astructure including a connector by a resin material.

DESCRIPTION OF REFERENCE SYMBOLS

-   -   1: Electronic pen    -   2: Casing of an electronic pen    -   3: Electronic pen main unit    -   4: Knock cam mechanism unit    -   7: Core body holding component    -   8: Writing pressure detecting unit    -   9: Printed board    -   10: Capacitor for power storage    -   12BT: Secondary cell    -   30: Casing of an electronic pen main unit    -   31: Main body tubular part    -   32: Tubular joining component    -   33: Peripheral electrode    -   34: Front cap    -   35: Center electrode (core body)

The various embodiments described above can be combined to providefurther embodiments. These and other changes can be made to theembodiments in light of the above-detailed description. In general, inthe following claims, the terms used should not be construed to limitthe claims to the specific embodiments disclosed in the specificationand the claims, but should be construed to include all possibleembodiments along with the full scope of equivalents to which suchclaims are entitled. Accordingly, the claims are not limited by thedisclosure.

The invention claimed is:
 1. An electronic pen main unit that isconfigured as a replaceable cartridge to be fitted to a fitting partpositioned in a casing of an electronic pen in which a pen tip side thatis one end side of the electronic pen in an axial center directionincludes an opening, and configured to be housed in a state of beingmovable in a hollow part of the casing by a movement mechanism thatmoves the fitting part in the axial center direction, the electronic penmain unit comprising: a pen tip part including anelectrically-conductive core body configured to protrude externally fromthe casing through the opening by being moved by the movement mechanism;a main body tubular part to which the pen tip part is joined on the pentip side in the axial center direction, the main body tubular parthousing an electronic circuit including a signal generating circuitconfigured to generate a signal to be transmitted by the core body; anda rear-end-part connector that is positioned at a rear end part of themain body tubular part on a side opposite from the pen tip part in theaxial center direction, includes a plurality of annular terminalsarranged at a plurality of different locations along the axial centerdirection of the replaceable cartridge and electrically insulated fromeach other and electrically connected to the electronic circuit, and isconfigured to be joined to a joining connector positioned at the fittingpart, wherein the joining connector includes a plurality of contactterminals, wherein the plurality of annular terminals are configured tobe electrically coupled to the plurality of contact terminals when thereplaceable cartridge is received in the casing and the rear-end-partconnector is joined to the joining connector, and at least one of theplurality of annular terminals is a power-supply annular terminalconfigured to be electrically coupled to one of the contact terminals tosupply power from a power source to the electronic circuit of thereplaceable cartridge.
 2. The electronic pen main unit according toclaim 1, wherein the plurality of annular terminals are electricallyinsulated from each other, and the rear-end-part connector and thejoining connector are configured to be joined through insertion of afitting protrusion of one of the rear-end-part connector or the joiningconnector into a fitting recess of the other of the rear-end-partconnector or the joining connector in the axial center direction.
 3. Theelectronic pen main unit according to claim 2, wherein the rear-end-partconnector includes the fitting protrusion, and the plurality of annularterminals include circular annular conductor contact parts having centerpositions that are aligned with each other in the axial centerdirection.
 4. The electronic pen main unit according to claim 2, whereinthe joining connector includes the fitting protrusion, the plurality ofcontact terminals of the joining connector include circular annularconductor contact parts having center positions that are aligned witheach other and are at different positions in the axial center direction,and the plurality of annular terminals of the rear-end-part connectorare configured to contact the circular annular conductor contact partsof the plurality of contact terminals of the joining connector.
 5. Theelectronic pen main unit according to claim 1, wherein the pen tip partincludes: a center electrode having one end side in the axial centerdirection that becomes a pen tip and that configures the core body, anda peripheral electrode that is positioned around the center electrodeexcept at least around the pen tip, and is electrically insulated fromthe center electrode.
 6. The electronic pen main unit according to claim5, wherein, in a case where the one end side that becomes the pen tip inthe center electrode protrudes externally from the casing through theopening, a part of the peripheral electrode on the pen tip sideprotrudes externally from the casing through the opening.
 7. Theelectronic pen main unit according to claim 1, wherein a power storageelement is positioned in the main body tubular part, the power storageelement configured to supply a supply voltage to the electronic circuit,and the power-supply annular terminal is configured to supply a chargingcurrent sent through the joining connector to the power storage element.8. The electronic pen main unit according to claim 1, wherein the powersource is a battery which is positioned in the casing and outside theelectronic pen main unit, and the power-supply annular terminal isconfigured to receive a voltage of the battery as a supply voltage ofthe electronic circuit.
 9. The electronic pen main unit according toclaim 1, wherein another electronic circuit is positioned in the hollowpart of the casing, and the plurality of annular terminals of therear-end-part connector include an annular terminal configured toelectrically connect the electronic circuit and the another electroniccircuit to each other.
 10. The electronic pen main unit according toclaim 1, wherein the plurality of annular terminals of the rear-end-partconnector include an annular terminal electrically connected to a sideswitch positioned on the casing in such a manner as to be operable by auser.
 11. The electronic pen main unit according to claim 1, wherein therear-end-part connector is one of a connector plug or a connector jack,and the joining connector is the other of the connector plug or theconnector jack.
 12. An electronic pen, comprising: a tubular casingincluding an opening at one end side of the electronic pen in an axialcenter direction that is a pen tip side; a fitting part including ajoining connector having a plurality of contact terminals; a movementmechanism configured to move the fitting part in the axial centerdirection; and an electronic pen main unit configured as a replaceablecartridge in the tubular casing, a rear end part side of the electronicpen main unit on a side opposite from the pen tip side being coupled tothe fitting part, the electronic pen main unit including: a pen tip partincluding an electrically-conductive core body configured to protrudeexternally from the tubular casing through the opening through movementof the fitting part by the movement mechanism; a main body tubular partto which the pen tip part is joined on the pen tip side in the axialcenter direction, the main body tubular part housing an electroniccircuit including a signal generating circuit configured to generate asignal to be transmitted by the core body, and a rear-end-part connectorthat is positioned at a rear end part of the main body tubular part on aside opposite from the pen tip part in the axial center direction,includes a plurality of annular terminals arranged at a plurality ofdifferent locations along the axial center direction of the replaceablecartridge and electrically insulated from each other and electricallyconnected to the electronic circuit, and is configured to be joined tothe joining connector, wherein the plurality of annular terminals areconfigured to be electrically coupled to the plurality of contactterminals when the replaceable cartridge is received in the tubularcasing and the rear-end-part connector is joined to the joiningconnector, and at least one of the plurality of annular terminals is apower-supply annular terminal configured to be electrically coupled toone of the contact terminals to supply power from a power source to theelectronic circuit of the replaceable cartridge.
 13. The electronic penaccording to claim 12, wherein: the power source is a charging electrodepositioned on the tubular casing; and the electronic pen furthercomprises a power storage element positioned in the main body tubularpart, the power storage element configured to supply a supply voltage tothe electronic circuit, wherein the charging electrode is electricallyconnected to a first contact terminal part of the joining connector, thepower-supply annular terminal is electrically connected to theelectronic circuit in such a manner as to supply a charging current tothe power storage element, and the first contact terminal and thepower-supply terminal are electrically connected in a case where therear-end-part connector is joined to the joining connector.
 14. Theelectronic pen according to claim 12, wherein: the power source is acharging coil mounted on the tubular casing, the charging coilconfigured to generate a current for charging by electromagneticinduction; and the electronic pen further comprises a power storageelement positioned in the main body tubular part, the power storageelement configured to supply a supply voltage to the electronic circuit,wherein the charging coil is electrically connected to a first contactterminal of the joining connector, the power-supply annular terminal iselectrically connected to the electronic circuit in such a manner as tosupply a charging current to the power storage element, and the firstcontact terminal and the power-supply annular terminal are electricallyconnected in a case where the rear-end-part connector is joined to thejoining connector.
 15. The electronic pen according to claim 12,wherein: the power source is a battery positioned in the tubular casing,the battery is electrically connected to a first contact terminal of thejoining connector, the power-supply annular terminal is electricallyconnected to a power supply path of the electronic circuit, and thefirst contact terminal and the power-supply annular terminal areelectrically connected in a case where the rear-end-part connector isjoined to the joining connector.
 16. The electronic pen according toclaim 15, wherein the battery is a rechargeable battery, and a chargingelectrode positioned on the tubular casing is used when the battery ischarged.
 17. The electronic pen according to claim 12, furthercomprising: a side switch positioned on the tubular casing in such amanner as to be operable by a user, wherein the electronic circuitincludes an information generating circuit configured to determine astate of the side switch and generate information for transmitting thestate of the side switch to a position detecting device, the side switchis electrically connected to a first contact terminal of the joiningconnector, the rear-end-part connector includes a second annularterminal electrically connected to the information generating circuit,and the first contact terminal and the second annular terminal areelectrically connected in a case where the rear-end-part connector isjoined to the joining connector.
 18. The electronic pen according toclaim 12, further comprising: a wireless communication part positionedin the tubular casing, the wireless communication part configured tocarry out wireless communication with a position detecting device,wherein a writing pressure detecting unit configured to detect a writingpressure applied to a pen tip of the electronic pen main unit or anidentification information generating part configured to generateidentification information of the electronic pen main unit is includedin the electronic pen main unit, and information regarding the writingpressure detected by the writing pressure detecting unit or theidentification information generated by the identification informationgenerating part is supplied to the wireless communication part throughthe rear-end-part connector and the joining connector and is transmittedthrough the wireless communication part.
 19. The electronic penaccording to claim 12, wherein the movement mechanism includes a knockmechanism of a knock-type ballpoint pen.
 20. The electronic penaccording to claim 12, wherein the movement mechanism includes amechanism of a knock-type multi-color ballpoint pen configured toselectively move one fitting part of a plurality of fitting parts, andat least one of the plurality of fitting parts is the fitting partincluding the joining connector.